docs: def assert_succeeds(exception, msg_fmt="{msg}"):
      """Fail if a specific exception is raised within the context.
  
      This assertion should be used for cases, where successfully running a
      function signals a successful test, and raising the exception of a
      certain type signals a test failure. All other raised exceptions are
      passed on and will usually still result in a test error. This can be
      used to signal the intent of a block.
  
      >>> l = ["foo", "bar"]
      >>> with assert_succeeds(ValueError):
      ...     i = l.index("foo")
      ...
      >>> with assert_succeeds(ValueError):
      ...     raise ValueError()
      ...
      Traceback (most recent call last):
          ...
      AssertionError: ValueError was unexpectedly raised
      >>> with assert_succeeds(ValueError):
      ...     raise TypeError("Wrong Error")
      ...
      Traceback (most recent call last):
          ...
      TypeError: Wrong Error
  
      The following msg_fmt arguments are supported:
      * msg - the default error message
      * exc_type - exception type
      * exc_name - exception type name
      * exception - exception that was raised
      """
  
      class _AssertSucceeds(object):
          def __enter__(self):
              pass
  
          def __exit__(self, exc_type, exc_val, exc_tb):
              if exc_type and issubclass(exc_type, exception):
                  msg = exception.__name__ + " was unexpectedly raised"
                  fail(
                      msg_fmt.format(
                          msg=msg,
                          exc_type=exception,
                          exc_name=exception.__name__,
                          exception=exc_val,
                      )
                  )
  
      return _AssertSucceeds()